Well this baffle must be nice rather than diffraction friendly. It is RC1 and will change a bit. Made of fiberglass with brax paste and local reinforcement.
Do you have any analysis data to show? Or is this just a "gut feeling" type of design?
"Well this baffle must be nice rather than diffraction friendly."
It could be both if the radii were different, assuming the sharp edge were radiused.
It could be both if the radii were different, assuming the sharp edge were radiused.
Hi jzagaja,
I agree with noah. Not so much change is needed, and you keep the good looks (which I agree is also very important).
I still can't figure out, is diffraction really audible? If it is, then how is it perceived? what should I listen for in a sound? Some people say it affects imaging, I have not found it to be the case. Free air small waveguide images the same as one flush mounted in a baffle.
Everything in my experience indicates that diffraction is audible. Your experiences are not the same as my experiences, but maybe that's because your test used "small" waveguides. I would describe it as blurring the image and making the speakers themselves not "disappear". With low diffraction the image is very solid and the speakers simply disappear.
Be aware that some other effects might mask diffraction audibility. However, it is measurable.
Post 1174 was the above (page 118)
Can you elaborate? It may be elsewhere in the ginormous thread, which does repeat itself quite often. I'm in the process of start-to-finishing it, and it's quite tiresome at (you guessed it, page 118) but this point jumped out at me. Is there some construction aspect of screw-on that you're not fond of? Is it a structural or acoustical issue you're concerned with? Does it tend to mean an increased throat length or some such?
The driver I'm planning my waveguide experimentation around is the JBL 2426H, which has an integral bolt-on adaptor but also a screw-on mounting under the adaptor.
I bought a cheap horn with screw mount and a cheap screw mount driver
I was very dissapointed to see that no effort had been made to try and make a smooth transistion
The throath of the horn is half an inch wider than drivers exit hole
I was very dissapointed to see that no effort had been made to try and make a smooth transistion
The throath of the horn is half an inch wider than drivers exit hole
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Yes, its poor design
Its the only waveguide I have ever had in my hands, and I have no experience with other
Is it a common design flaw, or an exception ?
Its the only waveguide I have ever had in my hands, and I have no experience with other
Is it a common design flaw, or an exception ?
It is very common. I have never seen a screw on driver that had anything approaching a well designed throat transition except in very expensive drivers (Goto, etc.).
I'll be interested to see how the 2426 is in this regard. JBL is not known for terrible transducer design.
The problem is that it's not the transducer design - it's the system integration. If the horn and driver are designed to work together, maybe it will be okay (although not always...). But if you screw on any old horn, it is unlikely to match up well to the throat of the driver in my experience.
Okay. You mean a screw on horn-driver combo, not just the throat area in the driver. That was unclear. Thanks.
Its a structural thing, not enough sterngth at a critical point in the structure. The very heavy driver is cantalevered off of the waveguide/horn at its smallest point. Not a good design. This connection needs to be fairly large and structurally quite rigid.
Cool. As a DIYer not relying upon the horn to support the weight of the driver, it's a non-issue for me. Thanks for the reply.
Just for the heck of it, I mounted a ribbon on one of my Unity horns yesterday. Sounded really nice. Here's some subjective impressions:
- strings sound really amazing. This would be a great option for someone who's into a lot of guitar rock. You can hear "texture" in the strings that's masked by a conventional compression driver.
- It's very revealing, but not "etched." For instance, reverb and studio tricks in a recording were more obvious than with a compression driver.
- Compared to my BMS 4540NDs, the ribbons had much less output in the top octave. I tried to add it back via EQ, but it sounded strained when I did so. Basically the BMS is eq-friendly; the ribbon is not.
- I measured the response, and it was flat from 800hz to 10khz... almost four octaves.
- I didn't have the guts to do a distortion measurement, but the BMS was clearly lower in distortion.
In a nutshell, the ribbon on a horn was very revealing, but had less extended response than the BMS, and more distortion. In the short term, it was fun to hear details in the recording that the BMS missed, but the distortion grew annoying.
This is all academic though - the ribbon failed after two hours of listening.